Hinged Three-Dimensional Structure Formed With Two-Dimensional Sheet of Material

ABSTRACT

A substantially two-dimensional sheet material is configured for bending along a bend line to form a three-dimensional structure having a hinge along the bend line. The sheet material includes a substantially two-dimensional in a region in which a bend is to be made, and a plurality of displacements in a thickness direction of the sheet material along opposing sides of the bend line, each displacement having a sheared edge extending between end portions thereof and substantially parallel to the bend line. The adjacent sheared edges overlap one another with respect to the bend line to form a hinge structure therebetween extending along the bend line, the hinge structure having hinge ends that conform in shape with the end portions. The hinge structure is dimensioned and configured for multiple bend and unbend cycles thereby providing a monolithic hinge connecting opposing panels of the sheet material on opposing sides of the bend line. A method of preparing and using the hinged three-dimensional structure is also disclosed.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/974,468 filed Sep. 22, 2007, entitled Hinged Three-DimensionalStructure Formed With Two-Dimensional Sheet Of Material, the entirecontents of which is incorporated herein for all purposes by thisreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates, in general, to two-dimensional sheet materialsconfigured to form hinged three-dimensional structures and methods fortheir use.

2. Description of Related Art

Various methods of preparing sheet materials for precision folding alonga desired bend line have been developed. For example, U.S. Pat. Nos.6,877,349, 6,877,349, 7,032,426, 7,152,449 and 7,152,450 describevarious methods of preparing and folding sheet materials for formingthree-dimensional objects having relatively high dimensional tolerancesfrom substantially planar two-dimensional sheets.

The folding-structures shown and described in the above patents promoteso-called edge-to-face engagement and other phenomena to facilitatefolding along a desired bending line. For example, as discussed in theabove-mentioned '450 patent, displacements may be formed to facilitatebending along a desired bend line.

The three-dimensional objects formed may be enclosures and otherstructural items having an interior and/or other form of compartment. Inmany instances, periodic access to the interior may be necessary forassembly and construction, maintenance and services, and/or otherpurposes. Generally, disassembly to some degree is necessary in order toaccess the interior. Alternatively, a door or other discrete hingedmember may be provided to ease access. Disadvantageously, such a memberrequires a discrete door, a discrete hinge, and other parts andfasteners which increase part count, complicates assembly and generallyrequires more time space and labor.

It would therefore be useful to provide a sheet of material havingbend-controlling structures that not only facilitate bending forassembly, but also provide an integral hinge structure to reduce partcount, simplify assembly, and/or facilitate access.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention is directed to a method of preparinga substantially two-dimensional sheet material for bending along a bendline to form a three-dimensional structure having a hinge along the bendline. The method may include one or more of the following steps:obtaining a sheet material that is substantially two-dimensional in aregion in which a bend is to be made; and forming a plurality ofdisplacements in a thickness direction of the sheet material alongopposing sides of the bend line, each displacement having a sheared edgeextending between end portions thereof and substantially parallel to thebend line. Adjacent sheared edges overlap one another with respect tothe bend line to form a hinge structure therebetween extending along thebend line, the hinge structure having hinge ends that conform in shapewith the end portions. The hinge structure is dimensioned and configuredfor multiple bend and unbend cycles thereby providing a monolithic hingeconnecting opposing panels of the sheet material on opposing sides ofthe bend line.

The obtaining step may be accomplished by obtaining a mild steel sheetmaterial. The forming step may be accomplished by forming thedisplacement such that the sheared edge may be a distance from the bendline that may be at least 75% the thickness (“T”) of the sheet material.The forming step may be accomplished by forming the displacement shearededges with the substantially linear portion extending between curvedportions, and such that adjacent sheared linear portions and curvedportions overlap one another for a distance that may be at leastapproximately 6T. The forming step may be accomplished by formingdisplacement faces opposing the displacement sheared edges, the methodmay further include the step of bending one of the opposing panelsrelative the other opposing panel about the bend line to produceedge-to-face engagement between at least a portion of the sheared edgesand a portion of the respective displacement faces.

The method may further include the step of bending one of the opposingpanels about the bend line relative to the other opposing panel. Themethod may further include the step of bending one of the opposingpanels about the bend line relative to the other opposing panel. Themethod may further include the step of bending and unbending the oneopposing panel about the bend line relative to the other opposing panelat least 25 times, preferably at least 35 times, and most preferably atleast 50 times. The method may further include the step of assemblingthe sheet material into a three-dimensional structure wherein one of theopposing panels provides a hinged panel for the three-dimensionalstructure that can be opened and closed.

Another aspect of the present invention is directed to a substantiallytwo-dimensional sheet material configured for bending along a bend lineto form a three-dimensional structure having a hinge along the bendline. The sheet material includes a sheet material substantiallytwo-dimensional in a region in which a bend is to be made, and aplurality of displacements in a thickness direction of the sheetmaterial along opposing sides of the bend line, each displacement havinga sheared edge extending between end portions thereof and substantiallyparallel to the bend line. The adjacent sheared edges may overlap oneanother with respect to the bend line to form a hinge structuretherebetween extending along the bend line, the hinge structure havinghinge ends that conform in shape with the end portions. The hingestructure is dimensioned and configured for multiple bend and unbendcycles thereby providing a monolithic hinge connecting opposing panelsof the sheet material on opposing sides of the bend line.

The sheet material may be mild steel. The sheared edge may be a distancefrom the bend line that may be at least 75% the thickness (“T”) of thesheet material. The substantially linear portion may extend betweencurved portions, and wherein adjacent sheared linear and curved portionsoverlap one another for a distance that may be at least approximately6T.

The sheet material may further include displacement faces opposing thedisplacement sheared edges, the displacements configured to produceedge-to-face engagement between at least a portion of the sheared edgesand a portion of the respective displacement faces while bending one ofthe opposing panels relative the other opposing panel about the bendline. The hinge structure may be configured to bend and unbend at least25 times. The hinge structure may be configured to bend and unbend atleast 50 times.

In other embodiments, a three-dimensional structure may include thesheet materials described above, wherein one of the opposing panelsforms a hinged access cover for access to a portion of thethree-dimensional structure. The three-dimensional structure may be abox, and the hinged access cover may be a lid providing access to aninterior portion of the three dimensional structure.

A further aspect of the present invention is directed to a substantiallytwo-dimensional sheet material configured for bending along a bend lineto form a three-dimensional structure having a hinge along the bendline. The sheet material includes a sheet material substantiallytwo-dimensional in a region in which a bend is to be made, and aplurality of tongues positioned along opposing sides of the bend line,each tongue having a face directed toward the bend line and extendingsubstantially parallel to the bend line, the tongue extending betweenend portions diverging away from the bend line. The adjacent faces mayoverlap one another with respect to the bend line to form a hingestructure therebetween extending along the bend line, the hingestructure having hinge roots that conform in shape with the endportions. The hinge structure may be dimensioned and configured formultiple bend and unbend cycles thereby providing a monolithic hingeconnecting opposing panels of the sheet material on opposing sides ofthe bend line.

The methods and sheets of the present invention have other features andadvantages which will be apparent from or are set forth in more detailin the accompanying drawings, which are incorporated herein for allpurposes, and the following Detailed Description of the Invention, whichtogether serve to explain certain principles of the present inventions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of an exemplary two-dimensional sheet materialdimensioned and configured to form a hinged three-dimensional structurein accordance with various aspects of the present invention, and FIG. 1Bis an enlarged detail thereof.

FIG. 2 is an isometric view of a portion the sheet material of FIG. 1,and an enlarged detail thereof, illustrating displacements in the sheetmaterial along a bend line forming hinge structures therebetween inaccordance with various aspects of the present invention.

FIG. 3 is an isometric view of the sheet material of FIG. 1 showingflanges thereof in a bent position.

FIG. 4 is an isometric view of the sheet material of FIG. 1 showingsides thereof in a bent position.

FIG. 5 is an isometric view of the sheet material of FIG. 1 showing atop thereof in a bent position.

FIG. 6 is an isometric view of the sheet material of FIG. 1 showing thetop in a closed position, thereby forming a three-dimensional structurein the form of an enclosure.

FIG. 7 is an isometric view of the sheet material of FIG. 1 showing thetop in an opened position, thereby allowing access to the interior ofthe three-dimensional structure.

FIG. 8 is an isometric view of a portion of the sheet material of FIG.1, and an enlarged detail thereof illustrating the hinge structuresafter the sheet material has been bent along the bend line.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various embodiments of thepresent inventions, examples of which are illustrated in theaccompanying drawings and described below. While the inventions will bedescribed in conjunction with exemplary embodiments, it will beunderstood that the present description is not intended to limit theinventions to those exemplary embodiments. On the contrary, theinventions is/are intended to cover not only the exemplary embodiments,but also various alternatives, modifications, equivalents and otherembodiments, which may be included within the spirit and scope of theinvention as defined by the appended claims.

Turning now to the drawings, wherein like components are designated bylike reference numerals throughout the various figures, attention isdirected to FIGS. 1A and B and FIG. 2 which disclose an exemplarytwo-dimensional (2D) sheet material 30 that has been dimensioned andconfigured to form a three-dimensional (3D) structure in the form of anenclosure 32 having a hinged access cover 33. As described in thebelow-mentioned patents and patent applications, there are numerousapplications in which 2D sheet materials can be formed into 3Dstructures.

The depiction of an enclosure is merely exemplary; the teachings of thepresent inventions for precision bending are also applicable to theproduction of numerous other 3D structures having hinged panelsincluding, but not limited to, electronic component chasses, automotivecomponents, transport components, construction components, appliancesparts, truck components, RF shields, HVAC components, aerospacecomponents, and more. That is, the teachings of the present applicationare applicable to a wide variety of 3D products and structures that areformed by folding 2D sheet materials, and which would benefit with theprovision of a hinged access cover. Such 3D structures may also benefitin that the present invention would allow reducing the 3D structures totheir flat forms to facilitate repackaging and reshipping. Such featureswould be particularly suited for producing reusable shipping containersand the like.

In many aspects, the sheet materials of the present inventions aresimilar to those disclosed by U.S. Pat. No. 6,481,259, U.S. Pat. No.6,877,349, U.S. Pat. No. 7,152,449, U.S. Pat. No. 7,152,450, U.S. patentapplication Ser. No. 10/821,818 (Pub. No. 2005/0005670), U.S. Pat. No.7,032,426, U.S. Pat. No. 7,263,869, U.S. Pat. No. 7,222,511, U.S. patentapplication Ser. No. 11/357,934 (Pub. No. 2006/0261139), U.S. Pat. No.7,374,810, U.S. patent application Ser. No. 11/384,216 (Pub. No.2006/0207212), U.S. Pat. No. 7,350,390, U.S. patent application Ser. No.11/374,828 (Pub. No. 2006/0213245), U.S. patent application Ser. No.11/180,398 (Pub. No. 2006/0021413), U.S. patent application Ser. No.11/290,968 (Pub. No. 2006/0075798), U.S. patent application Ser. No.11/411,440 (Pub. No. 2007/0113614), U.S. Provisional Patent ApplicationNo. 60/665,577, U.S. patent application Ser. No. 11/386,463 (Pub. No.2006/0277965), and U.S. Provisional Patent Application No. 60/854,846,the entire contents of which patents and patent applications areincorporated herein for all purposes by this reference.

The sheet material is formed of a non-compressible material. Suitablematerials include relatively ductile materials such as metal and thelike, including but are not limited to mild steel, raw and treatedsteels such a galvanized steel, stainless steel, aluminum, and alloysthereof.

Sheet material 30 includes a plurality of bending structures 35 formedin the sheet material that are positioned along bend lines 37 in amanner similar to that described in the above-mentioned patents andpatent applications. In the illustrated embodiment, the bend lines areconfigured to define enclosure sides 39 and enclosure ends 40 extendingfrom an enclosure base 42 as well as enclosure sides 39′ extending fromaccess cover 33. The bending structures are formed and oriented to allowprecise folding of the sheet material along the bend lines to ultimatelyposition the base, sides ends and access cover in a desired relationshipto form the 3D enclosure. One will appreciate that the number, position,and relative orientation of the bending structures and bend lines willvary depending upon the desired shape of the desired 3D structure.

In the illustrated embodiment, the bending structures 35 extend alongone side of bend lines 37 to facilitate bending therealong in order tobend the 2D sheet material into a 3D structure, as shown in FIG. 1A. Onewill appreciate that the bending structures may be formed along opposingsides of the bend lines to facilitate bending, as described in theabove-mentioned patents and patent applications. In the exemplaryembodiment, the bending structures are displacements, however, one willappreciate that other bending structures may be utilized such as theslits, displacements, grooves and/or other bend-inducing structuresdescribed in the above-mentioned patents and patent applications.

In accordance with the present inventions, certain bend lines may beconfigured to serve as a hinge monolithically formed with the remainderof the sheet material. For example, the exemplary embodiment includesone hinged bend line 44 that is configured to serve as a hinge 46allowing access cover 33 to be bent back and forth multiple times thusproviding enclosure 32 with a hinged access cover allowing access to theinterior of the enclosure (see, e.g., FIG. 5, FIG. 6 and FIG. 7). Onewill appreciate that the sheet of material may be provided with one,two, three or more hinged bend lines should multiple hinged panels bedesired. In addition, the 2D sheet materials may be provided with one ormore hinged punch-outs which would allow local access. For example,hinged bend line 44′ is configured to serve as a hinge 46′ allowingknockout panel to similarly be bent back and forth.

Hinged bend line 44 includes displacements 47 located on either side ofhinged bend line 44. The displacements, in many respects, are similar tothose described in the above-mentioned patents and applications. Forexample, each displacement 47 includes a tongue 49 which is displacedfrom the overall planar surface of sheet material 30. An exemplaryembodiment of the tongue is shown in FIG. 2 and FIG. 1B, the formerbeing a top view showing how tongue 49 is displaced above the overallplanar surface of sheet material, while the latter figure is a bottomview showing the depression into the sheet material formed by thedisplacement of the tongue.

The exemplary tongue extends substantially parallel to the planarportion of the sheet material, and remains connected to the remainder ofthe sheet material by an inclined transition zone 51. The flat andparallel configuration of the exemplary tongue may promote tool life andother advantages, however, one will appreciate that the tongue need notbe flat and/or exactly parallel to the remainder of the sheet material.Opposite transition zone 51 is a sheared face 53 extending along alength of displacement 47. In the exemplary embodiment, the sheared facehas a relatively straight central portion 53′ and curved end portions53″ that diverge away from the bend line. The displacements may beformed by stamping, punching, roll forming and/or other suitable meanssimilar to those discussed in the above mentioned patents andapplications.

While displacements 47 along hinged bend line 44 may have a similargeneral configuration as displacements utilized elsewhere on the sheetmaterial, the location and placement of displacements 47 relative tohinged bend line and relative to one another is particularly suited toserve as hinge 46. In particular, displacements 47 are positioned onalternating sides of hinged bend line 44 as shown in FIG. 1A and FIG.1B. More particularly, displacements 47 are spaced away from the hingedbend line in an overlapping fashion relative to adjacent displacements.Preferably, the length of overlap is greater than approximately 6 to 7times the thickness (“T”) of the sheet material. Increasing the lengthof overlap distributes axial torsion over a greater length and thusprovides a good hinge geometry for various applications.

Also, the displacements are preferably located a distance from thehinged bend line that is at least approximately 75% to 100% to 125% thethickness of the sheet material, which corresponds to a jog (“J”)distance between overlapping of approximately 1.5T to 2T. In someembodiments, the jog may be as wide as 3T or 4T. Such placement allowsfabrication using otherwise conventional stamping, punching androll-forming techniques.

Such configuration of the displacements generally define hingestructures 54 which extend between overlapping portions of adjacentdisplacements 47. A portion of the hinge structure extends along acrosshinged bend line 44 interconnecting opposing panel portions, and in thecase of the exemplary embodiment, interconnecting enclosure end 40′ toaccess cover 33. In addition, the hinge structure includes a divergingportion or root 56 that diverges away from the bend line which is formedby and conforms in shape with curved end portion 53″ of the shearedface. Also, the posture of the root after folding is largely formed byits contact with the adjacent displacement 47. Preferably, the curvedend portion has a relatively large radii of curvature which serves as astress reducer to distribute stress at the ends of hinge structure 54.The radii of curvature of curved end portion 53″ is preferably greaterthan the thickness of the sheet material, preferably two or three timesgreater than the thickness of the sheet material, and more preferablyapproximately three times the thickness or more.

The curved end portion serves to increase the cross-sectional area ofthe hinge structure as it connects to the remainder of the sheetmaterial. Such configuration is believed to distribute torsionalstresses within the hinge structure during bending (and unbending),which torsional stresses are schematically illustrated as arrows “T” inFIG. 1B. In addition, such configuration is believed to realign materialstresses at the end of the hinge structure with the adjacent material ofthe remainder of the sheet, which material stresses are schematicallyillustrated as arrows “B” FIG. 1B.

It has been demonstrated that such configuration significantly improvesthe number of bending/unbending cycles the hinge structure can withstandwithout failure. For example, exemplary configuration of mild steelsheet metal incorporating the hinge structure is capable of withstanding25 or more bending/unbending cycles without failure, and in someinstances, greater than 50 cycles without axial shear across and/orother propagation of shear vicinal the hinged bend line. Preferably thehinges are configured to withstand at least 35 cycles, more preferablyat least 45 cycles.

Such a configuration may also facilitate “strap” behavior that subjectsthe roots 56 of sheet material immediately adjacent the large-radii endsto tension and torsion (see, e.g., arrows “B” in FIG. 1B). The roots mayalso serve to facilitate precision bending along the bend line in thatthey appear to promote bend-assisting tension and torsion in a directionthat intersects the bend line.

Briefly, the folding of the above-described sheet materials is largelysimilar to the methods discussed extensively in the above-mentionedpatent applications and patents. The main difference is, upon completionof folding, hinge structures 54 allow repeated bending and unbendingalong hinged bend line 44 without material failure for certain number ofcycles that can be “designed” in the structure by varying certainparameters including the jog (e.g., hinge width) and the amount ofoverlap (e.g., hinge length).

Turning now to FIG. 3 through FIG. 7, a method of folding 2D sheetmaterial into a 3D structure may now be described. Exemplary sheetmaterial 30 is provided with a number of assembly side flanges 58 and anaccess cover flange 60. The side flanges are dimensioned and configuredto secure the sides and ends to one another once the sheet material hasbeen bent along its respective bend lines. In the exemplary embodiment,the side flanges and the assembly side flanges are provided withmonolithically formed cooperating latching means, similar to thatdescribed in U.S. patent application Ser. No. 11/386,463 (now Pub. No.2006/0277965), the entire contents of which application is incorporatedherein for all purposes by this reference. Access cover flange 60 isdimensioned and configured with similar latching means located on theopposing enclosure end 40. One will appreciate that other suitablelatching means may be utilized, and that no latching means need beprovided if so desired.

Preferably, the side and panel flanges are bent by stamping, punching,press-rolling or other suitable means, resulting in the orientationshown in FIG. 3. One will appreciate, however, that bending structuresmay be provided to facilitate bending of such flanges into position.

The enclosure sides 39 and enclosure ends 40 may then be bent relativeto the enclosure base 42, as shown in FIG. 4 and FIG. 5. As the sidesand ends are folded into position, the cooperating latching means willengage thereby securing side flanges 58 to the enclosure sides 39.Alternatively, the side flanges may be secured to the enclosure sides bywell known fastening means.

Finally, access cover 33 may be folded about hinge bend line 44 suchthat the access cover pivots down to its closed position, as shown inFIG. 6. Preferably, access cover flange is dimensioned and configured tocooperate with latching means provided on the opposing enclosure end 40to securely hold the access cover in its closed position. While suchlatching means may be self-locking, it may be preferable to forgo such aself-locking configuration in order to ease reopening of the accesscover. Alternatively, the access cover flange may be secured to theopposing enclosure end with well known fastening means.

As desired, access cover 33 may be reopened, as shown in FIG. 7, toallow access within the enclosure. For example, in the case thatenclosure 32 is an electrical component enclosure, it may be desirableto access the interior of the enclosure periodically. Hinge 46 allowssuch access while eliminating the need for a discrete hinge coupling theaccess cover to the remainder of the enclosure, and thus reduces partcount and assembly costs and complexity.

Turning back to FIG. 1A, knockout panel 33′ may be utilized in a similarmanner as the access cover. In addition, the 2D sheet materials may beprovided with one or more knockouts-outs 61, monolithically formed tabsinterconnecting a remote end of panel 33′ with the remainder of thesheet. Unlike conventional punch-out panels which become discretemembers once the tabs are broken, the panel 33′ remains connected to theremainder of the sheet material via monolithically formed hinge 46′.

For convenience in explanation and accurate definition in the appendedclaims, the terms “up” or “upper”, “down” or “lower”, “inside” and“outside” are used to describe features of the exemplary embodimentswith reference to the positions of such features as displayed in thefigures.

The foregoing descriptions of specific exemplary embodiments of thepresent inventions have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present inventions, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

1. A method of preparing a substantially two-dimensional sheet materialfor bending along a bend line to form a three-dimensional structurehaving a hinge along the bend line, the method comprising: obtaining asheet material that is substantially two-dimensional in a region inwhich a bend is to be made; and forming a plurality of displacements ina thickness direction of the sheet material along opposing sides of thebend line, each displacement having a sheared edge extending between endportions thereof and substantially parallel to the bend line, whereinadjacent sheared edges overlap one another with respect to the bend lineto form a hinge structure therebetween extending along the bend line,the hinge structure having hinge ends that conform in shape with the endportions; wherein the hinge structure is dimensioned and configured formultiple bend and unbend cycles thereby providing a monolithic hingeconnecting opposing panels of the sheet material on opposing sides ofthe bend line.
 2. The method of claim 1, wherein the obtaining step isaccomplished by obtaining a mild steel sheet material.
 3. The method ofclaim 1, wherein the forming step is accomplished by forming thedisplacement such that the sheared edge is a distance from the bend linethat is at least 75% the thickness (“T”) of the sheet material.
 4. Themethod of claim 3, wherein the forming step is accomplished by formingthe displacement sheared edges with the substantially linear portionextending between curved portions, and such that adjacent sheared linearportions and curved portions overlap one another for a distance that isat least approximately 6T.
 5. The method of claim 1, wherein the formingstep is accomplished by forming displacement faces opposing thedisplacement sheared edges, the method further comprising the step ofbending one of said opposing panels relative the other opposing panelabout the bend line to produce edge-to-face engagement between at leasta portion of the sheared edges and a portion of the respectivedisplacement faces.
 6. The method of claim 1, further comprising thestep of bending one of said opposing panels about the bend line relativeto the other opposing panel.
 7. The method of claim 1, furthercomprising the step of bending one of said opposing panels about thebend line relative to the other opposing panel.
 8. The method of claim7, further comprising the step of bending and unbending said oneopposing panel about the bend line relative to the other opposing panelat least 10 times.
 9. The method of claim 1, further comprising the stepof assembling the sheet material into a three-dimensional structurewherein one of said opposing panels provides a hinged panel for thethree-dimensional structure that can be opened and closed.
 10. Asubstantially two-dimensional sheet material configured for bendingalong a bend line to form a three-dimensional structure having a hingealong the bend line, the sheet material comprising: a sheet materialsubstantially two-dimensional in a region in which a bend is to be made;and a plurality of displacements in a thickness direction of the sheetmaterial along opposing sides of the bend line, each displacement havinga sheared edge extending between end portions thereof and substantiallyparallel to the bend line; wherein adjacent sheared edges overlap oneanother with respect to the bend line to form a hinge structuretherebetween extending along the bend line, the hinge structure havinghinge ends that conform in shape with the end portions; and wherein thehinge structure is dimensioned and configured for multiple bend andunbend cycles thereby providing a monolithic hinge connecting opposingpanels of the sheet material on opposing sides of the bend line.
 11. Thesheet material of claim 10, wherein the sheet material is mild steel.12. The sheet material of claim 10, wherein the sheared edge is adistance from the bend line that is at least 75% the thickness (“T”) ofthe sheet material.
 13. The sheet material of claim 10, wherein thedisplacement sheared edges comprise a substantially linear portion, andwherein adjacent sheared linear portions overlap one another for adistance that is at least approximately 3T.
 14. The sheet material ofclaim 13, wherein the substantially linear portion extends betweencurved portions, and wherein adjacent sheared linear and curved portionsoverlap one another for a distance that is at least approximately 5T.15. The sheet material of claim 10, further comprising displacementfaces opposing the displacement sheared edges, the displacementsconfigured to produce edge-to-face engagement between at least a portionof the sheared edges and a portion of the respective displacement faceswhile bending one of said opposing panels relative the other opposingpanel about the bend line.
 16. The sheet material of claim 10, the hingestructure is configured to bend and unbend at least 10 times.
 17. Thesheet material of claim 10, the hinge structure is configured to bendand unbend at least 50 times.
 18. A three-dimensional structurecomprising the sheet material claim 10, wherein one of said opposingpanels forms a hinged access cover for access to a portion of thethree-dimensional structure.
 19. The three-dimensional structure ofclaim 18, wherein the structure is a box, and the hinged access cover isa lid providing access to an interior portion of the three dimensionalstructure.
 20. A substantially two-dimensional sheet material configuredfor bending along a bend line to form a three-dimensional structurehaving a hinge along the bend line, the sheet material comprising: asheet material substantially two-dimensional in a region in which a bendis to be made; and a plurality of tongues positioned along opposingsides of the bend line, each tongue having a face directed toward thebend line and extending substantially parallel to the bend line, thetongue extending between end portions diverging away from the bend line;wherein adjacent faces overlap one another with respect to the bend lineto form a hinge structure therebetween extending along the bend line,the hinge structure having hinge roots that conform in shape with theend portions; and wherein the hinge structure is dimensioned andconfigured for multiple bend and unbend cycles thereby providing amonolithic hinge connecting opposing panels of the sheet material onopposing sides of the bend line.